1. Field of the Invention
The invention relates to a microstructure optical device for focusing X-rays, and more particularly to a method for manufacturing a parabolic type metallic compound refractive lens for focusing X-rays in two dimensions (2D).
2. Description of the Related Art
The original compound refractive lens for focusing X-rays is manufactured by a drilling method to drill an aluminum material to produce tens and hundreds of cylindrical bores arranged in order. X-rays is one-dimensionally focused, based on which, X-ray detection and diagnostic techniques are carried out. In order to improve the production precision, planar micro manufacturing technology (containing film deposition, optical lithography, electron beam lithography, ion beam lithography) is mostly employed to manufacture the compound refractive lens for focusing X-rays having a cross section in a circular, a parabolic, and a ellipsoid shape. Materials for manufacturing the compound refractive lens include aluminum, silicon, lithium, boron, carbon, aluminum oxide, and organic materials PMMA, so that the focus effect is highly improved, but the compound refractive lens is still one-dimensionally focused. However, in technical fields including X-ray detection and diagnostic techniques, X-ray detection spot (focal spot) is required within a micron or a sub-micron level rather than a focusing line. Thus, a compound refractive lens for focusing X-rays in two dimensions is necessitated.
Two typical methods for focusing of X-rays in two dimensions are described below. The first typical method includes: orthogonally placing two compound refractive lenses for focusing X-rays in one dimension; linearly focusing the X-ray beam in a horizontal direction and a vertical direction, respectively, thereby realizing the purpose of focusing X-rays in two dimensions. This method only requires manufacturing of one-dimensional compound refractive lens for focusing X-rays and does not relate to the manufacturing technology for the compound refractive lens for focusing X-rays in two dimensions. The second typical method is employing modeling technology to manufacture a compound refractive lens for focusing X-rays in two dimensions, that is, employing precise manufacturing technology to manufacture a die of lens refraction unit in a shape of paraboloid of revolution, pressing the aluminum material to form individual compound lens refraction units, and finally arranging the individual compound lens refraction units to form permutations and combinations, thus, the compound refractive lens for focusing X-rays in two dimensions is produced.